import java.util.Scanner;

public class Main {
	public static int buy(int s, int f, int h) {
		if(h > f)
			return 0;
		else if(h == 0)
			return 1;
		else
			return buy(s + 1, f - 1, h) + buy(s - 1, f, h - 1);
	}
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String input, output;
		String[] spInput;
		int f, h;
		
		while(sc.hasNext()) {
			input = sc.nextLine();
			spInput = input.split(",");
			f = Integer.parseInt(spInput[0]);
			h = Integer.parseInt(spInput[1]);
			
			output = Integer.toString(buy(0, f, h));
			
			System.out.println(output);
		}
	}
}